It is known that upon color development of silver halide color photographic materials, the oxidation products of aromatic primary amine color developing agents react with couplers to form indophenol, indoaniline, indamine, azomethine, phenoxazine, phenazine and similar dyes, thereby forming color images. In this system, color reproduction is usually accomplished by the subtractive color process; silver halide emulsions selectively sensitive to blue, green and red, and yellow, magenta and cyan color image-forming agents in a complementary relation therewith are used. For example, acylacetanilide or dibenzoylmethane type couplers are used to form yellow color images; pyrazolone, pyrazolobenzimidazole, pyrazolopyrazole, pyrazolotriazole, cyanoacetophenone or idazolone type couplers are mainly used to form magenta color images; and phenol type couplers, such as phenols and naphthols, are mainly used to form cyan color images.
Dyes formed from these couplers do not have ideal spectral absorption spectra. In particular, magenta dyes and cyan dyes have broad absorption spectra or undesirable subsidiary absorptions in a short wavelength region and thus they are not preferred in view of color reproduction of color photographic light-sensitive materials. Especially, the subsidiary absorption in a short wavelength region tends to bring about a decrease in saturation.
The decrease in saturation can be controlled to a certain extent by utilizing exhibition of an interimage effect. With respect to the interimage effect, this is described, for example, in Hanson et al., Journal of the Optical Society of America, Vol. 42, pages 663 to 669, and A. Thiels, Zeitschrift fur Wissenschaftliche Photographie, Photophysique und Photochemie, Vol. 47, pages 106 to 118 and 246 to 255.
Methods for obtaining perferable interimage effects are described in U.S. Pat. No. 3,536,486 wherein a diffusible 4-thiazoline-2-thione is incorporated into an exposed color reversal photographic element and in U.S. Pat. No. 3,536,487 wherein a diffusible 4-thiazoline-2-thione is incorporated into an unexposed color reversal photographic element.
Japanese Patent Publication No. 34169/73 (corresponding to U.S. Pat. No. 3,723,125) discloses that a remarkable interimage effect is obtained using a N-substituted 4-thiazoline-2-thione compound in the reduction of from silver halide to silver by the development of color photographic materials.
Further, providing a colloidal silver-containing layer between a cyan layer and a magenta layer in a color reversal photographic element for the purpose of obtaining a preferred interimage effect is described in Research Disclosure, No. 13116 (1975).
Moreover, a method for obtaining a favorable interimage effect is described in U.S. Pat. No. 4,082,553 wherein a color reversal photographic material having a layer arrangement which enables iodine ions to be mobilized during development comprises one layer containing silver haloiodide grains capable of forming latent images and another layer containing silver halide grains capable of forming latent images and surface fogged silver halide grains capable of being developed irrespectively of image exposure.
However, these methods described above still only provide an insufficient interimage effect and further the use of a layer containing colloidal silver and the incorporation of fogged silver halide grains have a severe problem in that a decrease in color density accompanies the color reversal photographic materials.
Furthermore, it is also known that an interimage effect can be achieved by using couplers (DIR couplers) capable of releasing development inhibiting substances such as benzotriazole derivatives or mercapto compounds at the time of the coupling reaction with oxidation products of color developing agents or hydroquinone compounds capable of releasing development inhibiting substances such as iodine ions or mercapto compounds at the time of development as described in U.S. Pat. Nos. 3,379,529, 3,620,746, 4,377,634 and 4,332,878, Japanese Patent Application (OPI) No. 129536/74 (corresponding to U.S. Pat. No. 3,930,863) (the term "OPI" as used herein refers to a "published unexamined Japanese patent application"), Japanese Patent Publication No. 24462/85, etc. However, the use of these compounds is attended by severe desensitization and causes a decrease in color density. Thus, their use is restricted.